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Kakiyama G, Minoiwa K, Bai-Kamara N, Hashiguchi T, Pandak WM, Rodriguez-Agudo D. StarD5 levels of expression correlate with onset and progression of steatosis and liver fibrosis. Am J Physiol Gastrointest Liver Physiol 2024; 326:G747-G761. [PMID: 38591148 PMCID: PMC11376981 DOI: 10.1152/ajpgi.00024.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/07/2024] [Accepted: 04/08/2024] [Indexed: 04/10/2024]
Abstract
Insufficient expression of steroidogenic acute regulatory-related lipid transfer protein 5 (StarD5) on liver cholesterol/lipid homeostasis is not clearly defined. The ablation of StarD5 was analyzed in mice on a normal or Western diet (WD) to determine its importance in hepatic lipid accumulation and fibrosis compared with wild-type (WT) mice. Rescue experiments in StarD5-/- mice and hepatocytes were performed. In addition to increased hepatic triglyceride (TG)-cholesterol levels, global StarD5-/- mice fed a normal diet displayed reduced plasma triglycerides and liver very low-density lipoprotein (VLDL) secretion as compared with WT counterparts. Insulin levels and homeostatic model assessment for insulin resistance (HOMA-IR) scoring were elevated, demonstrating developing insulin resistance (IR). WD-fed StarD5-/- mice upregulated WW domain containing transcription regulator 1 (TAZ or WWTR1) expression with accelerated liver fibrosis when compared with WD-fed WT mice. Suppression of oxysterol 7α-hydroxylase (CYP7B1) coupled with chronic accumulation of toxic oxysterol levels correlated with presentation of fibrosis. "Hepatocyte-selective" StarD5 overexpression in StarD5-/- mice restored expression, reduced hepatic triglycerides, and improved HOMA-IR. Observations in two additional mouse and one human metabolic dysfunction-associated steatotic liver disease (MASLD) model were supportive. The downregulation of StarD5 with hepatic lipid excess is a previously unappreciated physiological function appearing to promote lipid storage for future needs. Conversely, lingering downregulation of StarD5 with prolonged lipid-cholesterol excess accelerates fatty liver's transition to fibrosis; mediated via dysregulation in the oxysterol signaling pathway.NEW & NOTEWORTHY We have found that deletion of the cholesterol transport protein StarD5 in mice leads to an increase in insulin resistance and lipid accumulation due to the upregulation of lipid synthesis and decrease VLDL secretion from the liver. In addition, deletion of StarD5 increased fibrosis when mice were fed a Western diet. This represents a novel pathway of fibrosis development in the liver.
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Affiliation(s)
- Genta Kakiyama
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
- Research Services, Central Virginia Veterans Affairs Healthcare System, Richmond, Virginia, United States
| | - Kei Minoiwa
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
- Department of Pediatrics, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Nanah Bai-Kamara
- Research Services, Central Virginia Veterans Affairs Healthcare System, Richmond, Virginia, United States
| | - Taishi Hashiguchi
- Research and Development Bureau, SMC Laboratories, Inc., Tokyo, Japan
| | - William M Pandak
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
- Research Services, Central Virginia Veterans Affairs Healthcare System, Richmond, Virginia, United States
| | - Daniel Rodriguez-Agudo
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
- Research Services, Central Virginia Veterans Affairs Healthcare System, Richmond, Virginia, United States
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Wang Y, Ren J, Ren S. Larsucosterol: endogenous epigenetic regulator for treating chronic and acute liver diseases. Am J Physiol Endocrinol Metab 2024; 326:E577-E587. [PMID: 38381400 PMCID: PMC11376820 DOI: 10.1152/ajpendo.00406.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/15/2024] [Accepted: 02/15/2024] [Indexed: 02/22/2024]
Abstract
Larsucosterol, a potent endogenous epigenetic regulator, has been reported to play a significant role in lipid metabolism, inflammatory responses, and cell survival. The administration of larsucosterol has demonstrated a reduction in lipid accumulation within hepatocytes and the attenuation of inflammatory responses induced by lipopolysaccharide (LPS) and TNFα in macrophages, alleviating LPS- and acetaminophen (ATMP)-induced multiple organ injury, and decreasing mortalities in animal models. Results from phase 1 and 2 clinical trials have shown that larsucosterol has potential as a biomedicine for the treatment of acute and chronic liver diseases. Recent evidence suggests that larsucosterol is a promising candidate for treating alcohol-associated hepatitis with positive results from a phase 2a clinical trial, and for metabolic dysfunction-associated steatohepatitis (MASH) from a phase 1b clinical trial. In this review, we present a culmination of our recent research efforts spanning two decades. We summarize the discovery, physiological and pharmacological mechanisms, and clinical applications of larsucosterol. Furthermore, we elucidate the pathophysiological pathways of metabolic dysfunction-associated steatotic liver diseases (MASLD), metabolic dysfunction-associated steatohepatitis (MASH), and acute liver injuries. A central focus of the review is the exploration of the therapeutic potential of larsucosterol in treating life-threatening conditions, including acetaminophen overdose, endotoxin shock, MASLD, MASH, hepatectomy, and alcoholic hepatitis.
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Affiliation(s)
- Yaping Wang
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
- McGuire Veterans Affairs Medical Center, Richmond, Virginia, United States
| | - Jenna Ren
- Department of Pharmacology, Virginia Commonwealth University, Richmond, Virginia, United States
| | - Shunlin Ren
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
- McGuire Veterans Affairs Medical Center, Richmond, Virginia, United States
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Wang Y, Pandak WM, Hylemon PB, Min HK, Min J, Fuchs M, Sanyal AJ, Ren S. Cholestenoic acid as endogenous epigenetic regulator decreases hepatocyte lipid accumulation in vitro and in vivo. Am J Physiol Gastrointest Liver Physiol 2024; 326:G147-G162. [PMID: 37961761 PMCID: PMC11208024 DOI: 10.1152/ajpgi.00184.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/08/2023] [Accepted: 11/12/2023] [Indexed: 11/15/2023]
Abstract
Cholestenoic acid (CA) has been reported as an important biomarker of many severe diseases, but its physiological and pathological roles remain unclear. This study aimed to investigate the potential role of CA in hepatic lipid homeostasis. Enzyme kinetic studies revealed that CA specifically activates DNA methyltransferases 1 (DNMT1) at low concentration with EC50 = 1.99 × 10-6 M and inhibits the activity at higher concentration with IC50 = 9.13 × 10-6 M, and specifically inhibits DNMT3a, and DNMT3b activities with IC50= 8.41 × 10-6 M and IC50= 4.89 × 10-6 M, respectively. In a human hepatocyte in vitro model of high glucose (HG)-induced lipid accumulation, CA significantly increased demethylation of 5mCpG in the promoter regions of over 7,000 genes, particularly those involved in master signaling pathways such as calcium-AMPK and 0.0027 at 6 h. RNA sequencing analysis showed that the downregulated genes are affected by CA encoding key enzymes, such as PCSK9, MVK, and HMGCR, which are involved in cholesterol metabolism and steroid biosynthesis pathways. In addition, untargeted lipidomic analysis showed that CA significantly reduced neutral lipid levels by 60% in the cells cultured in high-glucose media. Administration of CA in mouse metabolic dysfunction-associated steatotic liver disease (MASLD) models significantly decreases lipid accumulation, suppresses the gene expression involved in lipid biosynthesis in liver tissues, and alleviates liver function. This study shows that CA as an endogenous epigenetic regulator decreases lipid accumulation via epigenetic regulation. The results indicate that CA can be considered a potential therapeutic target for the treatment of metabolic disorders.NEW & NOTEWORTHY To our knowledge, this study is the first to identify the mitochondrial monohydroxy bile acid cholestenoic acid (CA) as an endogenous epigenetic regulator that regulates lipid metabolism through epigenome modification in human hepatocytes. The methods used in this study are all big data analysis, and the results of each part show the global regulation of CA on human hepatocytes rather than narrow point effects.
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Affiliation(s)
- Yaping Wang
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
- McGuire Veterans Affairs Medical Center, Richmond, Virginia, United States
| | - Williams M Pandak
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
- McGuire Veterans Affairs Medical Center, Richmond, Virginia, United States
| | - Phillip B Hylemon
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
- McGuire Veterans Affairs Medical Center, Richmond, Virginia, United States
| | - Hae-Ki Min
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
- McGuire Veterans Affairs Medical Center, Richmond, Virginia, United States
| | - John Min
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
- McGuire Veterans Affairs Medical Center, Richmond, Virginia, United States
| | - Michael Fuchs
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
- McGuire Veterans Affairs Medical Center, Richmond, Virginia, United States
| | - Arun J Sanyal
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
- McGuire Veterans Affairs Medical Center, Richmond, Virginia, United States
| | - Shunlin Ren
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
- McGuire Veterans Affairs Medical Center, Richmond, Virginia, United States
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Dev S, Muchenditsi A, Gottlieb A, Deme P, Murphy S, Gabrielson KL, Dong Y, Hughes R, Haughey NJ, Hamilton JP, Lutsenko S. Oxysterol misbalance critically contributes to Wilson disease pathogenesis. SCIENCE ADVANCES 2022; 8:eadc9022. [PMID: 36260680 PMCID: PMC9581482 DOI: 10.1126/sciadv.adc9022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Wilson disease (WD) is a metabolic disorder caused by inactivation of the copper-transporting ATPase 2 (ATP7B) and copper (Cu) overload in tissues. Excess Cu causes oxidative stress and pathologic changes with poorly understood mechanistic connections. In Atp7b-/- mice with established liver disease, Cu overload activates the stress-sensitive transcription factor Nrf2 (nuclear factor erythroid-derived 2-like 2). Nrf2 targets, especially sulfotransferase 1e1 (Sult1e1), are strongly induced and cause elevation of sulfated sterols, whereas oxysterols are decreased. This sterol misbalance results in inhibition of the liver X receptor (LXR) and up-regulation of LXR targets associated with inflammatory responses. Pharmacological inhibition of Sult1e1 partially reverses oxysterol misbalance and LXR inhibition. Contribution of this pathway to advanced hepatic WD was demonstrated by treating mice with an LXR agonist. Treatment decreased inflammation by reducing expression of proinflammatory molecules, diminished fibrosis by down-regulating the noncanonical transforming growth factor-β signaling pathway, and improved liver morphology and function. Thus, the identified pathway is an important driver of WD.
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Affiliation(s)
- Som Dev
- Department of Physiology, Johns Hopkins University, School of Medicine, 725 North Wolfe St, Baltimore, MD 21205, USA
| | - Abigael Muchenditsi
- Department of Physiology, Johns Hopkins University, School of Medicine, 725 North Wolfe St, Baltimore, MD 21205, USA
| | - Aline Gottlieb
- Department of Physiology, Johns Hopkins University, School of Medicine, 725 North Wolfe St, Baltimore, MD 21205, USA
| | - Pragney Deme
- Department of Neurology, Johns Hopkins University, School of Medicine, 600 North Wolfe St, Baltimore, MD 21287, USA
| | - Sean Murphy
- Department of Biomedical Engineering, Johns Hopkins University, School of Medicine, 720 Rutland Ave, Baltimore, MD 21205, USA
| | - Kathleen L. Gabrielson
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University, School of Medicine, 733 North Broadway, Baltimore, MD 21205, USA
| | - Yixuan Dong
- Department of Physiology, Johns Hopkins University, School of Medicine, 725 North Wolfe St, Baltimore, MD 21205, USA
| | - Robert Hughes
- Department of Medicine, Johns Hopkins University, School of Medicine, 733 North Broadway, Baltimore, MD 21205, USA
| | - Norman J. Haughey
- Department of Neurology, Johns Hopkins University, School of Medicine, 600 North Wolfe St, Baltimore, MD 21287, USA
| | - James P. Hamilton
- Department of Medicine, Johns Hopkins University, School of Medicine, 733 North Broadway, Baltimore, MD 21205, USA
- Corresponding author. (S.L.); (J.P.H.)
| | - Svetlana Lutsenko
- Department of Physiology, Johns Hopkins University, School of Medicine, 725 North Wolfe St, Baltimore, MD 21205, USA
- Department of Medicine, Johns Hopkins University, School of Medicine, 733 North Broadway, Baltimore, MD 21205, USA
- Corresponding author. (S.L.); (J.P.H.)
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Mao S, Ren J, Xu Y, Lin J, Pan C, Meng Y, Xu N. Studies in the antiviral molecular mechanisms of 25-hydroxycholesterol: Disturbing cholesterol homeostasis and post-translational modification of proteins. Eur J Pharmacol 2022; 926:175033. [PMID: 35598845 PMCID: PMC9119167 DOI: 10.1016/j.ejphar.2022.175033] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/04/2022] [Accepted: 05/11/2022] [Indexed: 02/08/2023]
Abstract
Efficient antiviral drug discovery has been a pressing issue of global public health concern since the outbreak of coronavirus disease 2019. In recent years, numerous in vitro and in vivo studies have shown that 25-hydroxycholesterol (25HC), a reactive oxysterol catalyzed by cholesterol-25-hydroxylase, exerts broad-spectrum antiviral activity with high efficiency and low toxicity. 25HC restricts viral internalization and disturbs the maturity of viral proteins using multiple mechanisms. First, 25HC reduces lipid rafts and cholesterol in the cytomembrane by inhibiting sterol-regulatory element binding proteins-2, stimulating liver X receptor, and activating Acyl-coenzyme A: cholesterol acyl-transferase. Second, 25HC impairs endosomal pathways by restricting the function of oxysterol-binding protein or Niemann-pick protein C1, causing the virus to fail to release nucleic acid. Third, 25HC disturbs the prenylation of viral proteins by suppressing the sterol-regulatory element binding protein pathway and glycosylation by increasing the sensitivity of glycans to endoglycosidase. This paper reviews previous studies on the antiviral activity of 25HC in order to fully understand its role in innate immunity and how it may contribute to the development of urgently needed broad-spectrum antiviral drugs.
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Wang Y, Pandak WM, Lesnefsky EJ, Hylemon PB, Ren S. 25-Hydroxycholesterol 3-Sulfate Recovers Acetaminophen Induced Acute Liver Injury via Stabilizing Mitochondria in Mouse Models. Cells 2021; 10:3027. [PMID: 34831255 PMCID: PMC8616185 DOI: 10.3390/cells10113027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/29/2021] [Accepted: 11/03/2021] [Indexed: 12/20/2022] Open
Abstract
Acetaminophen (APAP) overdose is one of the most frequent causes of acute liver failure (ALF). N-acetylcysteine (NAC) is currently being used as part of the standard care in the clinic but its usage has been limited in severe cases, in which liver transplantation becomes the only treatment option. Therefore, there still is a need for a specific and effective therapy for APAP induced ALF. In the current study, we have demonstrated that treatment with 25-Hydroxycholesterol 3-Sulfate (25HC3S) not only significantly reduced mortality but also decreased the plasma levels of liver injury markers, including LDH, AST, and ALT, in APAP overdosed mouse models. 25HC3S also decreased the expression of those genes involved in cell apoptosis, stabilized mitochondrial polarization, and significantly decreased the levels of oxidants, malondialdehyde (MDA), and reactive oxygen species (ROS). Whole genome bisulfite sequencing analysis showed that 25HC3S increased demethylation of 5mCpG in key promoter regions and thereby increased the expression of those genes involved in MAPK-ERK and PI3K-Akt signaling pathways. We concluded that 25HC3S may alleviate APAP induced liver injury via up-regulating the master signaling pathways and maintaining mitochondrial membrane polarization. The results suggest that 25HC3S treatment facilitates the recovery and significantly decreases the mortality of APAP induced acute liver injury and has a synergistic effect with NAC in propylene glycol (PG) for the injury.
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Affiliation(s)
| | | | | | | | - Shunlin Ren
- Department of Internal Medicine, McGuire Veterans Affairs Medical Center, Virginia Commonwealth University, Richmond, VA 23249, USA; (Y.W.); (W.M.P.); (E.J.L.); (P.B.H.)
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Going "Green" in the Prevention and Management of Atherothrombotic Diseases: The Role of Dietary Polyphenols. J Clin Med 2021; 10:jcm10071490. [PMID: 33916712 PMCID: PMC8038361 DOI: 10.3390/jcm10071490] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/24/2021] [Accepted: 03/27/2021] [Indexed: 02/06/2023] Open
Abstract
During the 20th century processed and ready-to-eat foods became routinely consumed resulting in a sharp rise of fat, salt, and sugar intake in people's diets. Currently, the global incidence of obesity, raised blood lipids, hypertension, and diabetes in an increasingly aged population contributes to the rise of atherothrombotic events and cardiovascular diseases (CVD) mortality. Drug-based therapies are valuable strategies to tackle and help manage the socio-economic impact of atherothrombotic disorders though not without adverse side effects. The inclusion of fresh fruits and vegetables rich in flavonoids to human diets, as recommended by WHO offers a valuable nutritional strategy, alternative to drug-based therapies, to be explored in the prevention and management of atherothrombotic diseases at early stages. Though polyphenols are mostly associated to color and taste in foods, food flavonoids are emerging as modulators of cholesterol biosynthesis, appetite and food intake, blood pressure, platelet function, clot formation, and anti-inflammatory signaling, supporting the health-promoting effects of polyphenol-rich diets in mitigating the impact of risk factors in atherothrombotic disorders and CVD events. Here we overview the current knowledge on the effect of polyphenols particularly of flavonoid intake on the atherothrombotic risk factors and discuss the caveats and challenges involved with current experimental cell-based designs.
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8
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Wang Y, Lin W, Brown JE, Chen L, Pandak WM, Hylemon PB, Ren S. 25-Hydroxycholesterol 3-sulfate is an endogenous ligand of DNA methyltransferases in hepatocytes. J Lipid Res 2021; 62:100063. [PMID: 33705741 PMCID: PMC8058565 DOI: 10.1016/j.jlr.2021.100063] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/04/2021] [Accepted: 02/24/2021] [Indexed: 12/23/2022] Open
Abstract
The oxysterol sulfate, 25-hydroxycholesterol 3-sulfate (25HC3S), has been shown to play an important role in lipid metabolism, inflammatory response, and cell survival. However, the mechanism(s) of its function in global regulation is unknown. The current study investigates the molecular mechanism by which 25HC3S functions as an endogenous epigenetic regulator. To study the effects of oxysterols/sterol sulfates on epigenetic modulators, 12 recombinant epigenetic enzymes were used to determine whether 25HC3S acts as their endogenous ligand. The enzyme kinetic study demonstrated that 25HC3S specifically inhibited DNA methyltransferases (DNMTs), DNMT1, DNMT3a, and DNMT3b with IC50 of 4.04, 3.03, and 9.05 × 10-6 M, respectively. In human hepatocytes, high glucose induces lipid accumulation by increasing promoter CpG methylation of key genes involved in development of nonalcoholic fatty liver diseases. Using this model, whole genome bisulfate sequencing analysis demonstrated that 25HC3S converts the 5mCpG to CpG in the promoter regions of 1,074 genes. In addition, we observed increased expression of the demethylated genes, which are involved in the master signaling pathways, including MAPK-ERK, calcium-AMP-activated protein kinase, and type II diabetes mellitus pathways. mRNA array analysis showed that the upregulated genes encoded for key elements of cell survival; conversely, downregulated genes encoded for key enzymes that decrease lipid biosynthesis. Taken together, our results indicate that the expression of these key elements and enzymes are regulated by the demethylated signaling pathways. We summarized that 25HC3S DNA demethylation of 5mCpG in promoter regions is a potent regulatory mechanism.
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Affiliation(s)
- Yaping Wang
- Department of Internal Medicine, Virginia Commonwealth University/McGuire VA Medical Centre, Richmond, VA, USA; College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Weiqi Lin
- DURECT Corporation, Cupertino, CA, USA
| | | | - Lanming Chen
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Williams M Pandak
- Department of Internal Medicine, Virginia Commonwealth University/McGuire VA Medical Centre, Richmond, VA, USA
| | - Phillip B Hylemon
- Department of Internal Medicine, Virginia Commonwealth University/McGuire VA Medical Centre, Richmond, VA, USA
| | - Shunlin Ren
- Department of Internal Medicine, Virginia Commonwealth University/McGuire VA Medical Centre, Richmond, VA, USA.
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Lefort C, Cani PD. The Liver under the Spotlight: Bile Acids and Oxysterols as Pivotal Actors Controlling Metabolism. Cells 2021; 10:cells10020400. [PMID: 33669184 PMCID: PMC7919658 DOI: 10.3390/cells10020400] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 02/06/2023] Open
Abstract
Among the myriad of molecules produced by the liver, both bile acids and their precursors, the oxysterols are becoming pivotal bioactive lipids which have been underestimated for a long time. Their actions are ranging from regulation of energy homeostasis (i.e., glucose and lipid metabolism) to inflammation and immunity, thereby opening the avenue to new treatments to tackle metabolic disorders associated with obesity (e.g., type 2 diabetes and hepatic steatosis) and inflammatory diseases. Here, we review the biosynthesis of these endocrine factors including their interconnection with the gut microbiota and their impact on host homeostasis as well as their attractive potential for the development of therapeutic strategies for metabolic disorders.
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Wang Y, Li X, Ren S. Cholesterol Metabolites 25-Hydroxycholesterol and 25-Hydroxycholesterol 3-Sulfate Are Potent Paired Regulators: From Discovery to Clinical Usage. Metabolites 2020; 11:metabo11010009. [PMID: 33375700 PMCID: PMC7823450 DOI: 10.3390/metabo11010009] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/18/2020] [Accepted: 12/23/2020] [Indexed: 02/07/2023] Open
Abstract
Oxysterols have long been believed to be ligands of nuclear receptors such as liver × receptor (LXR), and they play an important role in lipid homeostasis and in the immune system, where they are involved in both transcriptional and posttranscriptional mechanisms. However, they are increasingly associated with a wide variety of other, sometimes surprising, cell functions. Oxysterols have also been implicated in several diseases such as metabolic syndrome. Oxysterols can be sulfated, and the sulfated oxysterols act in different directions: they decrease lipid biosynthesis, suppress inflammatory responses, and promote cell survival. Our recent reports have shown that oxysterol and oxysterol sulfates are paired epigenetic regulators, agonists, and antagonists of DNA methyltransferases, indicating that their function of global regulation is through epigenetic modification. In this review, we explore our latest research of 25-hydroxycholesterol and 25-hydroxycholesterol 3-sulfate in a novel regulatory mechanism and evaluate the current evidence for these roles.
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Affiliation(s)
- Yaping Wang
- Department of Internal Medicine, McGuire Veterans Affairs Medical Center, Virginia Commonwealth University, Richmond, VA 23249, USA;
| | - Xiaobo Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China;
| | - Shunlin Ren
- Department of Internal Medicine, McGuire Veterans Affairs Medical Center, Virginia Commonwealth University, Richmond, VA 23249, USA;
- Correspondence: ; Tel.: +1-(804)-675-5000 (ext. 4973)
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Jia W, Wei M, Rajani C, Zheng X. Targeting the alternative bile acid synthetic pathway for metabolic diseases. Protein Cell 2020; 12:411-425. [PMID: 33252713 PMCID: PMC8106556 DOI: 10.1007/s13238-020-00804-9] [Citation(s) in RCA: 156] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/21/2020] [Indexed: 12/12/2022] Open
Abstract
The gut microbiota is profoundly involved in glucose and lipid metabolism, in part by regulating bile acid (BA) metabolism and affecting multiple BA-receptor signaling pathways. BAs are synthesized in the liver by multi-step reactions catalyzed via two distinct routes, the classical pathway (producing the 12α-hydroxylated primary BA, cholic acid), and the alternative pathway (producing the non-12α-hydroxylated primary BA, chenodeoxycholic acid). BA synthesis and excretion is a major pathway of cholesterol and lipid catabolism, and thus, is implicated in a variety of metabolic diseases including obesity, insulin resistance, and nonalcoholic fatty liver disease. Additionally, both oxysterols and BAs function as signaling molecules that activate multiple nuclear and membrane receptor-mediated signaling pathways in various tissues, regulating glucose, lipid homeostasis, inflammation, and energy expenditure. Modulating BA synthesis and composition to regulate BA signaling is an interesting and novel direction for developing therapies for metabolic disease. In this review, we summarize the most recent findings on the role of BA synthetic pathways, with a focus on the role of the alternative pathway, which has been under-investigated, in treating hyperglycemia and fatty liver disease. We also discuss future perspectives to develop promising pharmacological strategies targeting the alternative BA synthetic pathway for the treatment of metabolic diseases.
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Affiliation(s)
- Wei Jia
- Center for Translational Medicine and Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China. .,School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
| | - Meilin Wei
- Center for Translational Medicine and Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Cynthia Rajani
- University of Hawaii Cancer Center, Honolulu, HI, 96813, USA
| | - Xiaojiao Zheng
- Center for Translational Medicine and Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.
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12
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Sanchez LD, Pontini L, Marinozzi M, Sanchez-Aranguren LC, Reis A, Dias IHK. Cholesterol and oxysterol sulfates: Pathophysiological roles and analytical challenges. Br J Pharmacol 2020; 178:3327-3341. [PMID: 32762060 DOI: 10.1111/bph.15227] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/01/2020] [Accepted: 07/20/2020] [Indexed: 01/18/2023] Open
Abstract
Cholesterol and oxysterol sulfates are important regulators of lipid metabolism, inflammation, cell apoptosis, and cell survival. Among the sulfate-based lipids, cholesterol sulfate (CS) is the most studied lipid both quantitatively and functionally. Despite the importance, very few studies have analysed and linked the actions of oxysterol sulfates to their physiological and pathophysiological roles. Overexpression of sulfotransferases confirmed the formation of a range of oxysterol sulfates and their antagonistic effects on liver X receptors (LXRs) prompting further investigations how are the changes to oxysterol/oxysterol sulfate homeostasis can contribute to LXR activity in the physiological milieu. Here, we aim to bring together for novel roles of oxysterol sulfates, the available techniques and the challenges associated with their analysis. Understanding the oxysterol/oxysterol sulfate levels and their pathophysiological mechanisms could lead to new therapeutic targets for metabolic diseases. LINKED ARTICLES: This article is part of a themed issue on Oxysterols, Lifelong Health and Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.16/issuetoc.
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Affiliation(s)
| | - Lorenzo Pontini
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Maura Marinozzi
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | | | - Ana Reis
- LAQV/REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
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Wang Y, Chen L, Pandak WM, Heuman D, Hylemon PB, Ren S. High Glucose Induces Lipid Accumulation via 25-Hydroxycholesterol DNA-CpG Methylation. iScience 2020; 23:101102. [PMID: 32408171 PMCID: PMC7225732 DOI: 10.1016/j.isci.2020.101102] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/01/2020] [Accepted: 04/22/2020] [Indexed: 12/12/2022] Open
Abstract
This work investigates the relationship between high-glucose (HG) culture, CpG methylation of genes involved in cell signaling pathways, and the regulation of carbohydrate and lipid metabolism in hepatocytes. The results indicate that HG leads to an increase in nuclear 25-hydroxycholesterol (25HC), which specifically activates DNA methyltransferase-1 (DNMT1), and regulates gene expression involved in intracellular lipid metabolism. The results show significant increases in 5mCpG levels in at least 2,225 genes involved in 57 signaling pathways. The hypermethylated genes directly involved in carbohydrate and lipid metabolism are of PI3K, cAMP, insulin, insulin secretion, diabetic, and NAFLD signaling pathways. The studies indicate a close relationship between the increase in nuclear 25HC levels and activation of DNMT1, which may regulate lipid metabolism via DNA CpG methylation. Our results indicate an epigenetic regulation of hepatic cell metabolism that has relevance to some common diseases such as non-alcoholic fatty liver disease and metabolic syndrome.
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Affiliation(s)
- Yaping Wang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China,Department of Internal Medicine, Virginia Commonwealth University/McGuire VA Medical Centre, Research 151, 1201 Broad Rock Boulevard, Richmond, VA 23249, USA
| | - Lanming Chen
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China
| | - William M. Pandak
- Department of Internal Medicine, Virginia Commonwealth University/McGuire VA Medical Centre, Research 151, 1201 Broad Rock Boulevard, Richmond, VA 23249, USA
| | - Douglas Heuman
- Department of Internal Medicine, Virginia Commonwealth University/McGuire VA Medical Centre, Research 151, 1201 Broad Rock Boulevard, Richmond, VA 23249, USA
| | - Phillip B. Hylemon
- Department of Internal Medicine, Virginia Commonwealth University/McGuire VA Medical Centre, Research 151, 1201 Broad Rock Boulevard, Richmond, VA 23249, USA
| | - Shunlin Ren
- Department of Internal Medicine, Virginia Commonwealth University/McGuire VA Medical Centre, Research 151, 1201 Broad Rock Boulevard, Richmond, VA 23249, USA.
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14
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Kumar DP, Santhekadur PK, Seneshaw M, Mirshahi F, Uram-Tuculescu C, Sanyal AJ. A Regulatory Role of Apoptosis Antagonizing Transcription Factor in the Pathogenesis of Nonalcoholic Fatty Liver Disease and Hepatocellular Carcinoma. Hepatology 2019; 69:1520-1534. [PMID: 30394550 PMCID: PMC6440548 DOI: 10.1002/hep.30346] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 10/29/2018] [Indexed: 01/02/2023]
Abstract
Hepatocellular carcinoma (HCC) is increasing as a cause of liver-related mortality largely because of the growing burden of nonalcoholic steatohepatitis (NASH). The mechanisms of HCC development in nonalcoholic fatty liver disease (NAFLD) are incompletely understood. We initially identified apoptosis antagonizing transcription factor (AATF) to be associated with HCC in a mouse model of NASH that develops HCC without the addition of specific carcinogens. AATF, also called che-1, is a transcriptional factor that is highly conserved among eukaryotes. AATF is known to be a central mediator of the cellular responses as it promotes cell proliferation and survival by inducing cell cycle arrest, autophagy, DNA repair, and inhibition of apoptosis. However, the role of AATF in NASH and HCC remains unknown. Here, we provide evidence for AATF as a contributory factor for HCC in NAFLD. AATF overexpression was further verified in human NASH and HCC and multiple human HCC cell lines. Tumor necrosis factor-α (TNFα), known to be increased in NASH, induced AATF expression. Promoter analysis of AATF revealed a sterol regulatory element binding transcription factor 1-c (SREBP-1c) binding site; inhibition of SREBP-1 by using specific inhibitors as well as small interfering RNA decreased TNFα-induced AATF expression. AATF interacted with signal transducer and activator of transcription 3 to increase monocyte chemoattractant protein-1 expression. AATF knockdown decreased cell proliferation, migration, invasion, colony formation, and anchorage-dependent growth in HCC cell lines. Xenograft of QGY-7703 HCC cells with AATF stably knocked down into nonobese diabetic scid gamma mice demonstrated reduced tumorigenesis and metastases. Conclusion: AATF drives NAFLD and hepatocarcinogenesis, offering a potential target for therapeutic intervention.
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Affiliation(s)
- Divya P. Kumar
- Division of Gastroenterology, Hepatology and Nutrition,
Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Prasanna K. Santhekadur
- Division of Gastroenterology, Hepatology and Nutrition,
Virginia Commonwealth University, Richmond, VA 23298, USA,Massey Cancer Center, Virginia Commonwealth University,
Richmond, VA 23298, USA
| | - Mulugeta Seneshaw
- Division of Gastroenterology, Hepatology and Nutrition,
Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Faridoddin Mirshahi
- Division of Gastroenterology, Hepatology and Nutrition,
Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Cora Uram-Tuculescu
- Department of Pathology, Virginia Commonwealth University,
Richmond, VA 23298, USA
| | - Arun J. Sanyal
- Division of Gastroenterology, Hepatology and Nutrition,
Virginia Commonwealth University, Richmond, VA 23298, USA,Massey Cancer Center, Virginia Commonwealth University,
Richmond, VA 23298, USA
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15
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Jang J, Lee JW, Song J, Kim D, Min KH. Exogenous Addition of 25-Hydroxycholesterol Reduces Level of Very Long-Chain Fatty Acids in X-Linked Adrenoleukodystrophy. ChemistryOpen 2019; 8:188-191. [PMID: 30788208 PMCID: PMC6369660 DOI: 10.1002/open.201800281] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/03/2019] [Indexed: 12/01/2022] Open
Abstract
X-Linked adrenoleukodystrophy (X-ALD) is a severe metabolic disorder characterized by the accumulation of very long-chain fatty acids (VLCFAs). Recently, we demonstrated that levels of 25-hydroxycholesterol (25-HC) and cholesterol 25-hydroxylase (CH25H) were found to be elevated in X-ALD. Herein, we report that the exogenous addition of 25-HC significantly reduces C26:0 levels in X-ALD patient-derived fibroblasts and oligodendrocytes differentiated from induced pluripotent stem cells (iPSCs) derived from X-ALD patients. Moreover, 25-HC treatment was found to down-regulate the expression of ELOVL1, a key enzyme for the synthesis of C26. In addition, activation of liver X receptor (LXR), a molecular target of endogenous 25-HC, also reduced C26:0 level. The reduction of C26:0 levels by 25-HC treatment might result, at least partially, from the decrease of ELOVL1 expression as well as the activation of LXR. Our findings could provide a better understanding of the role of 25-HC in X-ALD and useful information to find therapeutic agents to treat X-ALD.
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Affiliation(s)
- Jiho Jang
- Department of PhysiologyYonsei University College of MedicineSeoul03722Republic of Korea
| | - Jung Wuk Lee
- College of PharmacyChung-Ang UniversitySeoul06974Republic of Korea
| | - Jiho Song
- College of PharmacyChung-Ang UniversitySeoul06974Republic of Korea
| | - Dong‐Wook Kim
- Department of PhysiologyYonsei University College of MedicineSeoul03722Republic of Korea
| | - Kyung Hoon Min
- College of PharmacyChung-Ang UniversitySeoul06974Republic of Korea
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16
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Ning Y, Kim JK, Min HK, Ren S. Cholesterol metabolites alleviate injured liver function and decrease mortality in an LPS-induced mouse model. Metabolism 2017; 71:83-93. [PMID: 28521882 DOI: 10.1016/j.metabol.2016.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 12/01/2016] [Accepted: 12/07/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Oxysterol sulfation plays a fundamental role in the regulation of many biological events. Its products, 25-hydroxycholesterol 3-sulfate (25HC3S) and 25-hydroxycholesterol 3, 25-disulfate (25HCDS), have been demonstrated to be potent regulators of lipid metabolism, inflammatory response, cell apoptosis, and cell survival. In the present study, we tested these products' potential to treat LPS-induced acute liver failure in a mouse model. METHODS Acute liver failure mouse model was established by intravenous injection with LPS. The injured liver function was treated with intraperitoneal administration of 25HC, 25HC3S or 25HCDS. Serum enzymatic activities were determined in our clinic laboratory. ELISA assays were used to detect pro-inflammatory factor levels in sera. Western blot, Real-time Quantitative PCR and RT2 Profiler PCR Array analysis were used to determine levels of gene expression. RESULTS Administration of 25HC3S/25HCDS decreased serum liver-impaired markers; suppressed secretion of pro-inflammatory factors; alleviated liver, lung, and kidney injury; and subsequently increased the survival rate in the LPS-induced mouse model. These effects resulted from the inhibition of the expression of genes involved in the pro-inflammatory response and apoptosis and the simultaneous induction of the expression of genes involved in cell survival. Compared to 25HC, 25HC3S and 25HCDS exhibited significantly stronger effects in these activities, indicating that the cholesterol metabolites play an important role in the inflammatory response, cell apoptosis, and cell survival in vivo. CONCLUSIONS 25HC3S/25HCDS has potential to serve as novel biomedicines in the therapy of acute liver failure and acute multiple organ failure.
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Affiliation(s)
- Yanxia Ning
- Department of Internal Medicine, Virginia Commonwealth University/McGuire Veterans Affairs Medical Center, Richmond, VA 23249, United States
| | - Jin Kyung Kim
- Department of Internal Medicine, Virginia Commonwealth University/McGuire Veterans Affairs Medical Center, Richmond, VA 23249, United States
| | - Hae-Ki Min
- Department of Internal Medicine, Virginia Commonwealth University/McGuire Veterans Affairs Medical Center, Richmond, VA 23249, United States
| | - Shunlin Ren
- Department of Internal Medicine, Virginia Commonwealth University/McGuire Veterans Affairs Medical Center, Richmond, VA 23249, United States.
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17
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Mutemberezi V, Guillemot-Legris O, Muccioli GG. Oxysterols: From cholesterol metabolites to key mediators. Prog Lipid Res 2016; 64:152-169. [PMID: 27687912 DOI: 10.1016/j.plipres.2016.09.002] [Citation(s) in RCA: 234] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 09/13/2016] [Accepted: 09/23/2016] [Indexed: 12/13/2022]
Abstract
Oxysterols are cholesterol metabolites that can be produced through enzymatic or radical processes. They constitute a large family of lipids (i.e. the oxysterome) involved in a plethora of physiological processes. They can act through GPCR (e.g. EBI2, SMO, CXCR2), nuclear receptors (LXR, ROR, ERα) and through transporters or regulatory proteins. Their physiological effects encompass cholesterol, lipid and glucose homeostasis. Additionally, they were shown to be involved in other processes such as immune regulatory functions and brain homeostasis. First studied as precursors of bile acids, they quickly emerged as interesting lipid mediators. Their levels are greatly altered in several pathologies and some oxysterols (e.g. 4β-hydroxycholesterol or 7α-hydroxycholestenone) are used as biomarkers of specific pathologies. In this review, we discuss the complex metabolism and molecular targets (including binding properties) of these bioactive lipids in human and mice. We also discuss the genetic mouse models currently available to interrogate their effects in pathophysiological settings. We also summarize the levels of oxysterols reported in two key organs in oxysterol metabolism (liver and brain), plasma and cerebrospinal fluid. Finally, we consider future opportunities and directions in the oxysterol field in order to gain a better insight and understanding of the complex oxysterol system.
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Affiliation(s)
- Valentin Mutemberezi
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Belgium
| | - Owein Guillemot-Legris
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Belgium
| | - Giulio G Muccioli
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Belgium.
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18
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Guillemot-Legris O, Mutemberezi V, Muccioli GG. Oxysterols in Metabolic Syndrome: From Bystander Molecules to Bioactive Lipids. Trends Mol Med 2016; 22:594-614. [PMID: 27286741 DOI: 10.1016/j.molmed.2016.05.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/12/2016] [Accepted: 05/13/2016] [Indexed: 12/11/2022]
Abstract
Oxysterols are cholesterol metabolites now considered bona fide bioactive lipids. Recent studies have identified new receptors for oxysterols involved in immune and inflammatory processes, hence reviving their appeal. Through multiple receptors, oxysterols are involved in numerous metabolic and inflammatory processes, thus emerging as key mediators in metabolic syndrome. This syndrome is characterized by complex interactions between inflammation and a dysregulated metabolism. Presently, the use of synthetic ligands and genetic models has facilitated a better understanding of the roles of oxysterols in metabolism, but also raised interesting questions. We discuss recent findings on the absolute levels of oxysterols in tissues, their newly identified targets, and the mechanistic studies emphasizing their importance in metabolic disease, as there is a pressing need to further comprehend these intriguing bioactive lipids.
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Affiliation(s)
- Owein Guillemot-Legris
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Av. E.Mounier, 72 (B1.72.01), 1200 Bruxelles, Belgium
| | - Valentin Mutemberezi
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Av. E.Mounier, 72 (B1.72.01), 1200 Bruxelles, Belgium
| | - Giulio G Muccioli
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Av. E.Mounier, 72 (B1.72.01), 1200 Bruxelles, Belgium.
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19
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Upregulation of hydroxysteroid sulfotransferase 2B1b promotes hepatic oval cell proliferation by modulating oxysterol-induced LXR activation in a mouse model of liver injury. Arch Toxicol 2016; 91:271-287. [PMID: 27052460 DOI: 10.1007/s00204-016-1693-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 03/21/2016] [Indexed: 02/07/2023]
Abstract
Hydroxysteroid sulfotransferase 2B1b (SULT2B1b) sulfates cholesterol and oxysterols. Hepatic oval cells (HOCs), thought to be progenitor cells, can be triggered in chemically injured livers. The present study focused on the role of SULT2B1b in HOC proliferation after liver injury. Our experiments revealed that the expression of SULT2B1b was increased dramatically in a chemical-induced liver injury model, mainly in HOCs. Upon challenge with a hepatotoxic diet containing 0.1 % 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), SULT2B1-/- mice presented alleviated liver injury and less HOC proliferation compared with wild-type (WT) mice, and these findings were verified by serum analysis, histopathology, immunofluorescence staining, RNA-seq, and Western blotting. HOCs derived from SULT2B1-/- mice showed lower proliferative capability than those from WT mice. SULT2B1b overexpression promoted growth of the WB-F344 hepatic oval cell line, whereas SULT2B1b knockdown inhibited growth of these cells. The IL-6/STAT3 signaling pathway also was promoted by SULT2B1b. Liquid chromatography and mass spectrometry indicated that the levels of 22-hydroxycholesterol, 25-hydroxycholesterol, and 24,25-epoxycholesterol were higher in the DDC-injured livers of SULT2B1-/- mice than in livers of WT mice. The above oxysterols are physiological ligands of liver X receptors (LXRs), and SULT2B1b suppressed oxysterol-induced LXR activation. Additional in vivo and in vitro experiments demonstrated that LXR activation could inhibit HOC proliferation and the IL-6/STAT3 signaling pathway, and these effects could be reversed by SULT2B1b. Our data indicate that upregulation of SULT2B1b might promote HOC proliferation and aggravate liver injury via the suppression of oxysterol-induced LXR activation in chemically induced mouse liver injury.
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20
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Hepatotoxicity of piperazine designer drugs: up-regulation of key enzymes of cholesterol and lipid biosynthesis. Arch Toxicol 2016; 90:3045-3060. [DOI: 10.1007/s00204-016-1665-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/06/2016] [Indexed: 12/12/2022]
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21
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Seneff S, Davidson RM, Lauritzen A, Samsel A, Wainwright G. A novel hypothesis for atherosclerosis as a cholesterol sulfate deficiency syndrome. Theor Biol Med Model 2015; 12:9. [PMID: 26014131 PMCID: PMC4456713 DOI: 10.1186/s12976-015-0006-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/18/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Despite a vast literature, atherosclerosis and the associated ischemia/reperfusion injuries remain today in many ways a mystery. Why do atheromatous plaques make and store a supply of cholesterol and sulfate within the major arteries supplying the heart? Why are treatment programs aimed to suppress certain myocardial infarction risk factors, such as elevated serum homocysteine and inflammation, generally counterproductive? METHODS Our methods are based on an extensive search of the literature in atherosclerotic cardiovascular disease as well as in the area of the unique properties of water, the role of biosulfates in the vascular wall, and the role of electromagnetic fields in vascular flow. Our investigation reveals a novel pathology linked to atherosclerosis that better explains the observed facts than the currently held popular view. RESULTS We propose a novel theory that atherosclerosis can best be explained as being due to cholesterol sulfate deficiency. Furthermore, atheromatous plaques replenish the supply of cholesterol and sulfate to the microvasculature, by exploiting the inflammatory agent superoxide to derive sulfate from homocysteine and other sulfur sources. We argue that the sulfate anions attached to the glycosaminoglycans in the glycocalyx are essential in maintaining the structured water that is crucial for vascular endothelial health and erythrocyte mobility through capillaries. Sulfate depletion leads to cholesterol accumulation in atheromas, because its transport through water-based media depends on sulfurylation. We show that streaming potential induces nitric oxide (NO) release, and NO derivatives break down the extracellular matrix, redistributing sulfate to the microvasculature. We argue that low (less negative) zeta potential due to insufficient sulfate anions leads to hypertension and thrombosis, because these responses can increase streaming potential and induce nitric-oxide mediated vascular relaxation, promoting oxygen delivery. Our hypothesis is a parsimonious explanation of multiple features of atherosclerotic cardiovascular disease. CONCLUSIONS If our interpretation is correct, then it would have a significant impact on how atherosclerosis is treated. We recommend a high intake of sulfur-containing foods as well as an avoidance of exposure to toxicants that may impair sulfate synthesis.
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Affiliation(s)
- Stephanie Seneff
- Computer Science and Artificial Intelligence Laboratory, MIT, Cambridge, MA, 02139, USA.
| | - Robert M Davidson
- Internal Medicine Group Practice, PhyNet, Inc, 4002 Technology Center, Longview, TX, 75605, USA.
| | | | - Anthony Samsel
- Research Scientist and Consultant, Deerfield, NH, 03037, USA.
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22
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Ren S, Kim JK, Kakiyama G, Rodriguez-Agudo D, Pandak WM, Min HK, Ning Y. Identification of novel regulatory cholesterol metabolite, 5-cholesten, 3β,25-diol, disulfate. PLoS One 2014; 9:e103621. [PMID: 25072708 PMCID: PMC4114806 DOI: 10.1371/journal.pone.0103621] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 06/04/2014] [Indexed: 01/12/2023] Open
Abstract
Oxysterol sulfation plays an important role in regulation of lipid metabolism and inflammatory responses. In the present study, we report the discovery of a novel regulatory sulfated oxysterol in nuclei of primary rat hepatocytes after overexpression of the gene encoding mitochondrial cholesterol delivery protein (StarD1). Forty-eight hours after infection of the hepatocytes with recombinant StarD1 adenovirus, a water-soluble oxysterol product was isolated and purified by chemical extraction and reverse-phase HPLC. Tandem mass spectrometry analysis identified the oxysterol as 5-cholesten-3β, 25-diol, disulfate (25HCDS), and confirmed the structure by comparing with a chemically synthesized compound. Administration of 25HCDS to human THP-1-derived macrophages or HepG2 cells significantly inhibited cholesterol synthesis and markedly decreased lipid levels in vivo in NAFLD mouse models. RT-PCR showed that 25HCDS significantly decreased SREBP-1/2 activities by suppressing expression of their responding genes, including ACC, FAS, and HMG-CoA reductase. Analysis of lipid profiles in the liver tissues showed that administration of 25HCDS significantly decreased cholesterol, free fatty acids, and triglycerides by 30, 25, and 20%, respectively. The results suggest that 25HCDS inhibits lipid biosynthesis via blocking SREBP signaling. We conclude that 25HCDS is a potent regulator of lipid metabolism and propose its biosynthetic pathway.
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Affiliation(s)
- Shunlin Ren
- Department of Medicine, Veterans Affairs McGuire Medical Center/Department of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
| | - Jin Koung Kim
- Department of Medicine, Veterans Affairs McGuire Medical Center/Department of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Genta Kakiyama
- Department of Medicine, Veterans Affairs McGuire Medical Center/Department of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Daniel Rodriguez-Agudo
- Department of Medicine, Veterans Affairs McGuire Medical Center/Department of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - William M. Pandak
- Department of Medicine, Veterans Affairs McGuire Medical Center/Department of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Hae-Ki Min
- Department of Medicine, Veterans Affairs McGuire Medical Center/Department of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Yanxia Ning
- Department of Medicine, Veterans Affairs McGuire Medical Center/Department of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
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23
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Depression by a Green Tea Extract of Alcohol-Induced Oxidative Stress and Lipogenesis in Rat Liver. Biosci Biotechnol Biochem 2014; 75:1668-76. [DOI: 10.1271/bbb.110163] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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24
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Ren S, Ning Y. Sulfation of 25-hydroxycholesterol regulates lipid metabolism, inflammatory responses, and cell proliferation. Am J Physiol Endocrinol Metab 2014; 306:E123-30. [PMID: 24302009 PMCID: PMC3920008 DOI: 10.1152/ajpendo.00552.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Intracellular lipid accumulation, inflammatory responses, and subsequent apoptosis are the major pathogenic events of metabolic disorders, including atherosclerosis and nonalcoholic fatty liver diseases. Recently, a novel regulatory oxysterol, 5-cholesten-3b, 25-diol 3-sulfate (25HC3S), has been identified, and hydroxysterol sulfotransferase 2B1b (SULT2B1b) has been elucidated as the key enzyme for its biosynthesis from 25-hydroxycholesterol (25HC) via oxysterol sulfation. The product 25HC3S and the substrate 25HC have been shown to coordinately regulate lipid metabolism, inflammatory responses, and cell proliferation in vitro and in vivo. 25HC3S decreases levels of the nuclear liver oxysterol receptor (LXR) and sterol regulatory element-binding proteins (SREBPs), inhibits SREBP processing, subsequently downregulates key enzymes in lipid biosynthesis, decreases intracellular lipid levels in hepatocytes and THP-1-derived macrophages, prevents apoptosis, and promotes cell proliferation in liver tissues. Furthermore, 25HC3S increases nuclear PPARγ and cytosolic IκBα and decreases nuclear NF-κB levels and proinflammatory cytokine expression and secretion when cells are challenged with LPS and TNFα. In contrast to 25HC3S, 25HC, a known LXR ligand, increases nuclear LXR and decreases nuclear PPARs and cytosol IκBα levels. In this review, we summarize our recent findings, including the discovery of the regulatory oxysterol sulfate, its biosynthetic pathway, and its functional mechanism. We also propose that oxysterol sulfation functions as a regulatory signaling pathway.
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Affiliation(s)
- Shunlin Ren
- Departments of Medicine, McGuire Veterans Affairs Medical Center/Virginia Commonwealth University, Richmond, Virginia
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25
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Serviddio G, Blonda M, Bellanti F, Villani R, Iuliano L, Vendemiale G. Oxysterols and redox signaling in the pathogenesis of non-alcoholic fatty liver disease. Free Radic Res 2013; 47:881-93. [PMID: 24000796 DOI: 10.3109/10715762.2013.835048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Oxysterols are oxidized species of cholesterol coming from exogenous (e.g. dietary) and endogenous (in vivo) sources. They play critical roles in normal physiologic functions such as regulation of cellular cholesterol homeostasis. Most of biological effects are mediated by interaction with nuclear receptor LXRα, highly expressed in the liver as well as in many other tissues. Such interaction participates in the regulation of whole-body cholesterol metabolism, by acting as "lipid sensors". Moreover, it seems that oxysterols are also suspected to play key roles in several pathologies, including cardiovascular and inflammatory disease, cancer, and neurodegeneration. Growing evidence suggests that oxysterols may contribute to liver injury in non-alcoholic fatty liver disease. The present review focuses on the current status of knowledge on oxysterols' biological role, with an emphasis on LXR signaling and oxysterols' physiopathological relevance in NAFLD, suggesting new pharmacological development that needs to be addressed in the near future.
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Affiliation(s)
- G Serviddio
- C.U.R.E. Centre for Liver Diseases Research and Treatment, Institute of Internal Medicine, Department of Medical and Surgical Sciences, University of Foggia , Italy
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26
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Acimovic J, Lövgren-Sandblom A, Olin M, Ali Z, Heverin M, Schüle R, Schöls L, Fischler B, Fickert P, Trauner M, Björkhem I. Sulphatation does not appear to be a protective mechanism to prevent oxysterol accumulation in humans and mice. PLoS One 2013; 8:e68031. [PMID: 23844150 PMCID: PMC3700920 DOI: 10.1371/journal.pone.0068031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 05/24/2013] [Indexed: 01/10/2023] Open
Abstract
24S- and 27-hydroxycholesterol (24OHC and 27OHC) are potent regulators of different biochemical systems in vitro and are the major circulating oxysterols. A small fraction of these oxysterols has been reported to be sulphated but there are no detailed studies. We considered the possibility that sulphatation is a protective mechanism preventing accumulation of free oxysterols. Using an accurate assay we found the sulphated fraction of 24OHC and 27OHC in circulation of adults to be less than 15% of total. In two patients with a mutation in CYP7B1 and markedly increased levels of 27OHC the sulphated fraction was 8% and 10% respectively. Infants with severe neonatal cholestasis had however markedly increased sulphate fraction of the above oxysterols. In untreated mice the degree of sulphatation of 24OHC and 27OHC in serum varied between 0 and 16%. Similar degree of sulphatation was found in two mouse models with markedly increased levels of 27OHC and 24OHC respectively. Bile duct ligated mice had higher levels of oxysterols than sham-operated controls but the sulphate fraction was not increased. We conclude that a primary increase in the levels of the oxysterols due to increased synthesis or reduced metabolism in adults and mice does not induce increased sulphatation.
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Affiliation(s)
- Jure Acimovic
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
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Yang X, Xu Y, Guo F, Ning Y, Zhi X, Yin L, Li X. Hydroxysteroid sulfotransferase SULT2B1b promotes hepatocellular carcinoma cells proliferation in vitro and in vivo. PLoS One 2013; 8:e60853. [PMID: 23593328 PMCID: PMC3623875 DOI: 10.1371/journal.pone.0060853] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 03/03/2013] [Indexed: 01/12/2023] Open
Abstract
Hydroxysteroid sulfotransferase 2B1b (SULT2B1b) is highly selective for the addition of sulfate groups to 3β-hydroxysteroids. Although previous reports have suggested that SULT2B1b is correlated with cell proliferation of hepatocytes, the relationship between SULT2B1b and the malignant phenotype of hepatocarcinoma cells was not clear. In the present study, we found that SULT2B1 was comparatively higher in the human hepatocarcinoma tumorous tissues than their adjacent tissues. Besides, SULT2B1b overexpression promoted the growth of the mouse hepatocarcinoma cell line Hepa1-6, while Lentivirus-mediated SULT2B1b interference inhibited growth as assessed by the CCK-8 assay. Likewise, inhibition of SULT2B1b expression induced cell-cycle arrest and apoptosis in Hepa1-6 cells by upregulating the expression of FAS, downregulating the expression of cyclinB1, BCL2 and MYC in vitro and in vivo at both the transcript and protein levels. Knock-down of SULT2B1b expression significantly suppressed tumor growth in nude mouse xenografts. Moreover, proliferation rates and SULT2B1b expression were highly correlated in the human hepatocarcinoma cell lines Huh-7, Hep3B, SMMC-7721 and BEL-7402 cells. Knock-down of SULT2B1b inhibited cell growth and cyclinB1 levels in human hepatocarcinoma cells and suppressed xenograft growth in vivo. In conclusion, SULT2B1b expression promotes proliferation of hepatocellular carcinoma cells in vitro and in vivo, which may contribute to the progression of HCC.
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Affiliation(s)
- Xiaoming Yang
- Department of Physiology and Pathophysiology, Fudan University Shanghai Medical College, Shanghai, China
- Ningxia Medical University, Yinchuan, Ningxia, China
| | - Yali Xu
- Department of Physiology and Pathophysiology, Fudan University Shanghai Medical College, Shanghai, China
| | - Fenghua Guo
- General Surgery, Hua’shan Hospital, Fudan University Shanghai Medical College, Shanghai, China
| | - Yanxia Ning
- Department of Physiology and Pathophysiology, Fudan University Shanghai Medical College, Shanghai, China
| | - Xiuling Zhi
- Department of Physiology and Pathophysiology, Fudan University Shanghai Medical College, Shanghai, China
| | - Lianhua Yin
- Department of Physiology and Pathophysiology, Fudan University Shanghai Medical College, Shanghai, China
| | - Xiaobo Li
- Department of Physiology and Pathophysiology, Fudan University Shanghai Medical College, Shanghai, China
- * E-mail:
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Xu L, Kim JK, Bai Q, Zhang X, Kakiyama G, Min HK, Sanyal AJ, Pandak WM, Ren S. 5-cholesten-3β,25-diol 3-sulfate decreases lipid accumulation in diet-induced nonalcoholic fatty liver disease mouse model. Mol Pharmacol 2013; 83:648-58. [PMID: 23258548 PMCID: PMC3583496 DOI: 10.1124/mol.112.081505] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Sterol regulatory element-binding protein-1c (SREBP-1c) increases lipogenesis at the transcriptional level, and its expression is upregulated by liver X receptor α (LXRα). The LXRα/SREBP-1c signaling may play a crucial role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). We previously reported that a cholesterol metabolite, 5-cholesten-3β,25-diol 3-sulfate (25HC3S), inhibits the LXRα signaling and reduces lipogenesis by decreasing SREBP-1c expression in primary hepatocytes. The present study aims to investigate the effects of 25HC3S on lipid homeostasis in diet-induced NAFLD mouse models. NAFLD was induced by feeding a high-fat diet (HFD) in C57BL/6J mice. The effects of 25HC3S on lipid homeostasis, inflammatory responses, and insulin sensitivity were evaluated after acute treatments or long-term treatments. Acute treatments with 25HC3S decreased serum lipid levels, and long-term treatments decreased hepatic lipid accumulation in the NAFLD mice. Gene expression analysis showed that 25HC3S significantly suppressed the SREBP-1c signaling pathway that was associated with the suppression of the key enzymes involved in lipogenesis: fatty acid synthase, acetyl-CoA carboxylase 1, and glycerol-3-phosphate acyltransferase. In addition, 25HC3S significantly reduced HFD-induced hepatic inflammation as evidenced by decreasing tumor necrosis factor and interleukin 1 α/β mRNA levels. A glucose tolerance test and insulin tolerance test showed that 25HC3S administration improved HFD-induced insulin resistance. The present results indicate that 25HC3S as a potent endogenous regulator decreases lipogenesis, and oxysterol sulfation can be a key protective regulatory pathway against lipid accumulation and lipid-induced inflammation in vivo.
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Affiliation(s)
- Leyuan Xu
- McGuire Veterans Affairs Medical Center/Virginia Commonwealth University, Research 151, Richmond, VA 23249, USA
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29
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On the formation and possible biological role of 25-hydroxycholesterol. Biochimie 2013; 95:455-60. [DOI: 10.1016/j.biochi.2012.06.016] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 06/14/2012] [Indexed: 11/22/2022]
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Abstract
Emerging experimental and human evidence has linked altered hepatic cholesterol homeostasis and free cholesterol (FC) accumulation to the pathogenesis of non-alcoholic steatohepatits (NASH). This review focuses on cellular mechanisms of cholesterol toxicity involved in liver injury and on alterations in cholesterol homeostasis promoting hepatic cholesterol overload in NASH. FC accumulation injures hepatocytes directly, by disrupting mitochondrial and endoplasmic reticulum (ER) membrane integrity, triggering mitochondrial oxidative injury and ER stress, and by promoting generation of toxic oxysterols, and indirectly, by inducing adipose tissue dysfunction. Accumulation of oxidized LDL particles may also activate Kupffer and hepatic stellate cells, promoting liver inflammation and fibrogenesis. Hepatic cholesterol accumulation is driven by a deeply deranged cellular cholesterol homeostasis, characterized by elevated cholesterol synthesis and uptake from circulating lipoproteins and by a reduced cholesterol excretion. Extensive dysregulation of cellular cholesterol homeostasis by nuclear transcription factors sterol regulatory binding protein (SREBP)-2, liver X-receptor (LXR)-α and farnesoid X receptor (FXR) plays a key role in hepatic cholesterol accumulation in NASH. The therapeutic implications and opportunities for normalizing cellular cholesterol homeostasis in these patients are also discussed.
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Ogawa S, Kawamoto H, Mitsuma T, Fujimori H, Higashi T, Iida T. Stereoselective synthesis and NMR characterization of C-24 epimeric pairs of 24-alkyl oxysterols. Lipids 2012. [PMID: 23197084 DOI: 10.1007/s11745-012-3739-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Two pairs of C-24 epimeric (24R)-/(24S)-24-hydroxy-24-methyl-5α-cholestan-3β-yl acetates and (24R)-/(24S)-25-hydroxy-24-methyl-5α-cholestan-3β-yl acetates as well as some related 24-ethyl oxysterol analogs were stereoselectively synthesized directly from the respective parent 24-alkyl sterols by a remote O-insertion reaction with 2,6-dichloropyridine N-oxide (DCP) in the presence of a catalytic amount of (5,10,15,20-tetramesitylporphrinate) ruthenium(II) carbonyl complex [Ru(TMP)CO] and HBr. ¹H- and ¹³C-NMR signals serving to differentiate each of the two epimeric pairs were interpreted. The C-24 alkyl oxysterols epimeric at C-24 were found to be effectively characterized by the aromatic solvent-induced shift (ASIS) by C₅D₅N, particularly for the difference in the ¹³C resonances in the substituted cholestane side chain. A method for differentiating the ¹H and ¹³C signal assignment of the terminal 26-/27-CH₃ in the iso-octane side chain was also discussed on the basis of a combined use of the preferred conformational analysis and HMQC and HMBC techniques. The present method may be useful for determining the stereochemical configuration at C-24 of this type of 24-alkyl oxysterols.
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Affiliation(s)
- Shoujiro Ogawa
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba 278-8510, Japan
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32
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Zhang X, Bai Q, Kakiyama G, Xu L, Kim JK, Pandak WM, Ren S. Cholesterol metabolite, 5-cholesten-3β-25-diol-3-sulfate, promotes hepatic proliferation in mice. J Steroid Biochem Mol Biol 2012; 132:262-70. [PMID: 22732306 PMCID: PMC3463675 DOI: 10.1016/j.jsbmb.2012.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Revised: 06/11/2012] [Accepted: 06/13/2012] [Indexed: 11/21/2022]
Abstract
UNLABELLED Oxysterols are well known as physiological ligands of liver X receptors (LXRs). Oxysterols, 25-hydroxycholesterol (25HC) and 27-hydroxycholesterol as endogenous ligands of LXRs, suppress cell proliferation via LXRs signaling pathway. Recent reports have shown that sulfated oxysterol, 5-cholesten-3β-25-diol-3-sulfate (25HC3S) as LXRs antagonist, plays an opposite direction to oxysterols in lipid biosynthesis. The present report was to explore the effect and mechanism of 25HC3S on hepatic proliferation in vivo. Following administration, 25HC3S had a 48 h half life in the circulation and widely distributed in mouse tissues. Profiler™ PCR array and RTqPCR analysis showed that either exogenous or endogenous 25HC3S generated by overexpression of oxysterol sulfotransferase (SULT2B1b) plus administration of 25HC significantly up-regulated the proliferation gene expression of Wt1, Pcna, cMyc, cyclin A, FoxM1b, and CDC25b in a dose-dependent manner in liver while substantially down-regulating the expression of cell cycle arrest gene Chek2 and apoptotic gene Apaf1. Either exogenous or endogenous administration of 25HC3S significantly induced hepatic DNA replication as measured by immunostaining of the PCNA labeling index and was associated with reduction in expression of LXR response genes, such as ABCA1 and SREBP-1c. Synthetic LXR agonist T0901317 effectively blocked 25HC3S-induced hepatic proliferation. CONCLUSIONS 25HC3S may be a potent regulator of hepatocyte proliferation and oxysterol sulfation may represent a novel regulatory pathway in liver proliferation via inactivating LXR signaling.
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Affiliation(s)
- Xin Zhang
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
- Department of Pathology, Fudan University Shanghai Medical College, 138 Yixueyuan Road, Shanghai 200032, China
| | - Qianming Bai
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
- Department of Pathology, Fudan University Shanghai Cancer Center, 270 Dongan Road, Shanghai 200032, China
| | - Genta Kakiyama
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
| | - Leyuan Xu
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
| | - Jin Kyung Kim
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
| | - William M. Pandak
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
| | - Shunlin Ren
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
- Address correspondence to: Dr. Shunlin Ren McGuire Veterans Affairs Medical Center/Virginia Commonwealth University, Research 151, 1201 Broad Rock Blvd, Richmond, VA, 23249, USA. Tel.: +1 (804) 675-5000×4973 Fax: +1 (804) 675-5359
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Cha JY, Kim YB. Sulfated oxysterol 25HC3S as a therapeutic target of non-alcoholic fatty liver disease. Metabolism 2012; 61:1055-7. [PMID: 22592130 DOI: 10.1016/j.metabol.2012.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 04/11/2012] [Accepted: 04/11/2012] [Indexed: 11/21/2022]
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Plée-Gautier E, Antoun J, Goulitquer S, Le Jossic-Corcos C, Simon B, Amet Y, Salaün JP, Corcos L. Statins increase cytochrome P450 4F3-mediated eicosanoids production in human liver cells: A PXR dependent mechanism. Biochem Pharmacol 2012; 84:571-9. [DOI: 10.1016/j.bcp.2012.05.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 05/15/2012] [Accepted: 05/15/2012] [Indexed: 11/24/2022]
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Zhang X, Bai Q, Xu L, Kakiyama G, Pandak WM, Zhang Z, Ren S. Cytosolic sulfotransferase 2B1b promotes hepatocyte proliferation gene expression in vivo and in vitro. Am J Physiol Gastrointest Liver Physiol 2012; 303:G344-55. [PMID: 22679001 PMCID: PMC3423104 DOI: 10.1152/ajpgi.00403.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cytosolic sulfotransferase 2B1b (SULT2B1b) catalyzes the sulfation of 3β-hydroxysteroids and functions as a selective cholesterol and oxysterol sulfotransferase. Activation of liver X receptors (LXRs) by oxysterols has been known to be an antiproliferative factor. Overexpression of SULT2B1b impairs LXR's response to oxysterols, by which it regulates lipid metabolism. The aim of this study was to investigate in vivo and in vitro effects of SULT2B1b on liver proliferation and the underlying mechanisms. Primary rat hepatocytes and C57BL/6 mice were infected with adenovirus encoding SULT2B1b. Liver proliferation was determined by measuring the proliferating cell nuclear antigen (PCNA) immunostaining labeling index. The correlation between SULT2B1b and PCNA expression in mouse liver tissues was determined by double immunofluorescence. Gene expressions were evaluated by quantitative real-time PCR and Western blot analysis. SULT2B1b overexpression in mouse liver tissues increased PCNA-positive cells in a dose- and time-dependent manner. The increased expression of PCNA in mouse liver tissues was only observed in the SULT2B1b transgenic cells. Small interference RNA SULT2B1b significantly inhibited cell cycle regulatory gene expressions in primary rat hepatocytes. LXR activation by T0901317 effectively suppressed SULT2B1b-induced gene expression in vivo and in vitro. SULT2B1b may promote hepatocyte proliferation by inactivating oxysterol/LXR signaling.
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Affiliation(s)
- Xin Zhang
- 1Department of Pathology, Fudan University Shanghai Medical College, Shanghai, China; and ,2Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, Virginia
| | - Qianming Bai
- 1Department of Pathology, Fudan University Shanghai Medical College, Shanghai, China; and ,2Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, Virginia
| | - Leyuan Xu
- 2Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, Virginia
| | - Genta Kakiyama
- 2Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, Virginia
| | - William M. Pandak
- 2Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, Virginia
| | - Zhigang Zhang
- 1Department of Pathology, Fudan University Shanghai Medical College, Shanghai, China; and
| | - Shunlin Ren
- 2Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, Virginia
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36
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Polyzos SA, Kountouras J, Mantzoros CS. Sulfated oxysterols as candidates for the treatment of nonalcoholic fatty liver disease. Metabolism 2012; 61:755-8. [PMID: 22386938 DOI: 10.1016/j.metabol.2012.01.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 01/19/2012] [Indexed: 01/23/2023]
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37
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Lee FT, Kuo TY, Liou SY, Chien CT. Chronic Rhodiola rosea Extract Supplementation Enforces Exhaustive Swimming Tolerance. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2012; 37:557-72. [DOI: 10.1142/s0192415x09007053] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We explored the effects and mechanisms of Rhodiola rosea extract supplementation on swimming-induced fatigue in rats. The concentrations of active components in Rhodiola rosea have been determined by high performance liquid chromatography-mass spectrometer. The Rhodiola rosea extract supplementation in water for 2–4 weeks was evaluated in male Wistar rats with 90-min unloaded swimming exercise and 5% body weight loaded swimming up to fatigue. We measured the fatigue biomarkers, including blood urea nitrogen (BUN), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT), lactate dehydrogenase (LDH), hepatic glycogen content, the activity of fat metabolism enzymes, sterol regulatory element-binding protein-1 (SREBP-1) and fatty acid synthase (FAS), the tissue oxygen content and ratio of red and white skeletal muscle fibers in rats. Rhodiola rosea significantly increased liver glycogen, SREBP-1, FAS, heat shock protein 70 expression, Bcl-2/Bax ratio and oxygen content before swimming. Rhodiola rosea supplementation significantly increased the swimming time in a dose-dependent manner and reduced swimming-enhanced serum BUN, GOT and GPT levels. The ratio of red and white muscle fibers was not altered after chronic Rhodiola rosea extract supplementation. Chronic Rhodiola rosea supplementation significantly improved exhaustive swimming-induced fatigue by the increased glycogen content, energy supply of lipogenic enzyme expressions and protective defense mechanisms.
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Affiliation(s)
- Fang-Tsai Lee
- Department of Orthopaedic Surgery, Kuang-Tien General Hospital, Taichung, Taiwan
| | - Tz-Yin Kuo
- Department of Food Science, Nutrition, and Nutraceutical Biotechnology, Shih-Chien University College of Human Ecology, Taipei, Taiwan
- Department of Medical Research, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Shaw-Yih Liou
- Formosan Blood Purification Foundation, Taipei, Taiwan
| | - Chiang-Ting Chien
- Department of Medical Research, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
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38
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Xu L, Shen S, Ma Y, Kim JK, Rodriguez-Agudo D, Heuman DM, Hylemon PB, Pandak WM, Ren S. 25-Hydroxycholesterol-3-sulfate attenuates inflammatory response via PPARγ signaling in human THP-1 macrophages. Am J Physiol Endocrinol Metab 2012; 302:E788-99. [PMID: 22275753 PMCID: PMC3330710 DOI: 10.1152/ajpendo.00337.2011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The nuclear receptor peroxisome proliferator-activated receptors (PPARs) are important in regulating lipid metabolism and inflammatory responses in macrophages. Activation of PPARγ represses key inflammatory response gene expressions. Recently, we identified a new cholesterol metabolite, 25-hydroxycholesterol-3-sulfate (25HC3S), as a potent regulatory molecule of lipid metabolism. In this paper, we report the effect of 25HC3S and its precursor 25-hydroxycholesterol (25HC) on PPARγ activity and on inflammatory responses. Addition of 25HC3S to human macrophages markedly increased nuclear PPARγ and cytosol IκB and decreased nuclear NF-κB protein levels. PPARγ response element reporter gene assays showed that 25HC3S significantly increased luciferase activities. PPARγ competitor assay showed that the K(i) for 25HC3S was ∼1 μM, similar to those of other known natural ligands. NF-κB-dependent promoter reporter gene assays showed that 25HC3S suppressed TNFα-induced luciferase activities only when cotransfected with pcDNAI-PPARγ plasmid. In addition, 25HC3S decreased LPS-induced expression and release of IL-1β. In the PPARγ-specific siRNA transfected macrophages or in the presence of PPARγ-specific antagonist, 25HC3S failed to increase IκB and to suppress TNFα and IL-1β expression. In contrast to 25HC3S, its precursor 25HC, a known liver X receptor ligand, decreased nuclear PPARγ and cytosol IκB and increased nuclear NF-κB protein levels. We conclude that 25HC3S acts in macrophages as a PPARγ ligand and suppresses inflammatory responses via the PPARγ/IκB/NF-κB signaling pathway.
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Affiliation(s)
- Leyuan Xu
- Department of Medicine, Virginia Commonwealth University, Richmond, VA 23249, USA
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Eberhard Y, Gronda M, Hurren R, Datti A, MacLean N, Ketela T, Moffat J, Wrana JL, Schimmer AD. Inhibition of SREBP1 sensitizes cells to death ligands. Oncotarget 2011; 2:186-96. [PMID: 21406729 PMCID: PMC3260812 DOI: 10.18632/oncotarget.239] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Evasion of death receptor ligand-induced apoptosis contributs to cancer development and progression. To better understand mechanisms conferring resistance to death ligands, we screened an siRNA library to identify sequences that sensitize resistant cells to fas activating antibody (CH-11). From this screen, we identified the Sterol-Regulatory Element-Binding Protein 1 (SREBP1), a transcription factor, which regulates genes involved in cholesterol and fatty acid synthesis including fatty acid synthase. Inhibition of SREBP1 sensitized PPC-1 and HeLa to the death receptor ligands CH-11 and TRAIL. In contrast, DU145 prostate cancer cells that are resistant to death ligands despite expressing the receptors on their cell surface remained resistant to CH-11 and TRAIL after knockdown of SREBP1. Consistent with the effects on cell viability, the addition of CH-11 activated caspases 3 and 8 in HeLa but not DU145 cells with silenced SREBP1. We demonstrated that knockdown of SREBP1 produced a marked decrease in fatty acid synthase expression. Furthermore, genetic or chemical inhibition of fatty acid synthase with shRNA or orlistat, respectively, recapitulated the effects of SREBP1 inhibition and sensitized HeLa but not DU145 cells to CH-11 and TRAIL. Sensitization to death receptor ligands by inhibition of fatty acid synthase was associated with activation of caspase 8 prior to caspase 9. Neither silencing of SREBP1 or fatty acid synthase changed basal expression of the core death receptor components Fas, caspase 8, FADD, caspase 3 or FLIP. Thus, inhibition of SREBP1 or its downstream target fatty acid synthase sensitizes resistant cells to death ligands.
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Affiliation(s)
- Yanina Eberhard
- Princess Margaret Hospital, Ontario Cancer Institute, Toronto, ON, Canada
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40
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Bai Q, Xu L, Kakiyama G, Runge-Morris MA, Hylemon PB, Yin L, Pandak WM, Ren S. Sulfation of 25-hydroxycholesterol by SULT2B1b decreases cellular lipids via the LXR/SREBP-1c signaling pathway in human aortic endothelial cells. Atherosclerosis 2011; 214:350-6. [PMID: 21146170 PMCID: PMC3031658 DOI: 10.1016/j.atherosclerosis.2010.11.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 11/15/2010] [Accepted: 11/17/2010] [Indexed: 11/15/2022]
Abstract
OBJECTIVE 25-Hydroxycholesterol (25HC) and its sulfated metabolite, 25-hydroxycholesterol-3-sulfate (25HC3S), regulate certain aspects of lipid metabolism in opposite ways. Hence, the enzyme for the biosynthesis of 25HC3S, oxysterol sulfotransferase (SULT2B1b), may play a crucial role in regulating lipid metabolism. We evaluate the effect of 25HC sulfation on lipid metabolism by overexpressing the gene encoding SULT2B1b in human aortic endothelial cells (HAECs) in culture. METHODS AND RESULTS The human SULT2B1b gene was successfully overexpressed in HAECs following infection using a recombinant adenovirus. HPLC analysis demonstrated that more than 50% of (3)H-25HC was sulfated in 24h following overexpression of the SULT2B1b gene. In the presence of 25HC, SULT2B1b overexpression significantly decreased mRNA and protein levels of LXR, ABCA1, SREBP-1c, ACC-1, and FAS, which are key regulators of lipid biosynthesis and transport; and subsequently reduced cellular lipid levels. Overexpression of the gene encoding SULT2B1b gave similar results as adding exogenous 25HC3S. However, in the absence of 25HC or in the presence of T0901317, synthetic liver oxysterol receptor (LXR) agonist, SULT2B1b overexpression had no effect on the regulation of key genes involved in lipid metabolism. CONCLUSIONS Our data indicate that sulfation of 25HC by SULT2B1b plays an important role in the maintenance of intracellular lipid homeostasis via the LXR/SREBP-1c signaling pathway in HAECs.
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Affiliation(s)
- Qianming Bai
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, VA, 23249
- Department of Physiology and Pathophysiology, Fudan University Shanghai Medical College, Shanghai, China 200032
| | - Leyuan Xu
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, VA, 23249
| | - Genta Kakiyama
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, VA, 23249
| | | | - Phillip B. Hylemon
- Department of Microbiology/Immunology, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, VA, 23249
| | - Lianhua Yin
- Department of Physiology and Pathophysiology, Fudan University Shanghai Medical College, Shanghai, China 200032
| | - William M. Pandak
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, VA, 23249
| | - Shunlin Ren
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, Richmond, VA, 23249
- Address correspondence to: Dr. Shunlin Ren, McGuire Veterans Affairs Medical Center/Virginia Commonwealth University, Research 151, 1201 Broad Rock Blvd, Richmond, VA, 23249. Tel. (804) 675-5000 x 4973;
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Abstract
The dialogue between gut hormone, bile acids, and the brain plays an important role in energy homeostasis and the onset of Type 2 diabetes mellitus (T2DM). The present review focuses on: (i) bile acid metabolism and the role of bile acids in the regulation of both glucose homeostasis and the control of hypercholesterolemia; (ii) the role of gut hormones in energy homeostasis; and (iii) translation of the pathophysiology of bile acids and gut hormones into clinical practice. Although definitive mechanisms of action of gut hormones and bile acids have not been elucidated completely, these concepts allow us to understand several pharmacological interventions in the treatment of T2DM. Results from further clinical studies with related therapies will help us determine the role of these treatments in the management of energy homeostasis.
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Affiliation(s)
- Yifei Zhang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases and Division of Endocrine and Metabolic Diseases of E-Institutes of Shanghai Universities, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Xu L, Bai Q, Rodriguez-Agudo D, Hylemon PB, Heuman DM, Pandak WM, Ren S. Regulation of hepatocyte lipid metabolism and inflammatory response by 25-hydroxycholesterol and 25-hydroxycholesterol-3-sulfate. Lipids 2010; 45:821-32. [PMID: 20700770 DOI: 10.1007/s11745-010-3451-y] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 07/15/2010] [Indexed: 01/06/2023]
Abstract
Dysregulation of lipid metabolism is frequently associated with inflammatory conditions. The mechanism of this association is still not clearly defined. Recently, we identified a nuclear oxysterol, 25-hydroxycholesterol-3-sulfate (25HC3S), as an important regulatory molecule involved in lipid metabolism in hepatocytes. The present study shows that 25HC3S and its precursor, 25-hydroxycholesterol (25HC), diametrically regulate lipid metabolism and inflammatory response via LXR/SREBP-1 and IkappaBalpha/NFkappaB signaling in hepatocytes. Addition of 25HC3S to primary rat hepatocytes decreased nuclear LXR and SREBP-1 protein levels, down-regulated their target genes, acetyl CoA carboxylase 1 (ACC1), fatty acid synthase (FAS), and SREBP-2 target gene HMG reductase, key enzymes involved in fatty acid and cholesterol biosynthesis. 25HC3S reduced TNFalpha-induced inflammatory response by increasing cytoplasmic IkappaBalpha levels, decreasing NFkappaB nuclear translocation, and consequently repressing expression of NFkappaB-dependent genes, IL-1beta, TNFalpha, and TRAF1. NFkappaB-dependent promoter reporter gene assay showed that 25HC3S suppressed luciferase activity in the hepatocytes. In contrast, 25HC elicited opposite effects by increasing nuclear LXR and SREBP-1 protein levels, and by increasing ACC1 and FAS mRNA levels. 25HC also decreased cytoplasmic IkappaBalpha levels and further increased TNFalpha-induced NFkappaB activation. The current findings suggest that 25HC and 25HC3S serve as potent regulators in cross-talk of lipid metabolism and inflammatory response in the hepatocytes.
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Affiliation(s)
- Leyuan Xu
- Department of Medicine, McGuire Veterans Affairs Medical Center, Virginia Commonwealth University, Research 151, 1201 Broad Rock Blvd, Richmond, VA 23249, USA
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Ning YX, Ren SL, Zhao FD, Yin LH. Overexpression of the steroidogenic acute regulatory protein increases the expression of ATP-binding cassette transporters in microvascular endothelial cells (bEnd.3). J Zhejiang Univ Sci B 2010; 11:350-6. [PMID: 20443213 DOI: 10.1631/jzus.b0900369] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To determine the effect of steroidogenic acute regulatory protein (StAR) overexpression on the levels of adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) and ATP-binding cassette transporter G1 (ABCG1) in an endothelial cell line (bEnd.3). METHODS The StAR gene was induced in bEnd.3 cells with adenovirus infection. The infection efficiency was detected by fluorescence activated cell sorter (FACS) and fluorescence microscopy. The expressions of StAR gene and protein levels were detected by real-time polymerase chain reaction (PCR) and Western blot. The gene and protein levels of ABCA1 and ABCG1 were detected by real-time PCR and Western blot after StAR overexpression. RESULTS The result shows that StAR was successfully overexpressed in bEnd.3 cells by adenovirus infection. The mRNA and protein expressions of ABCA1 and ABCG1 were greatly increased by StAR overexpression in bEnd.3 cells. CONCLUSION Overexpression of StAR increases ABCA1 and ABCG1 expressions in endothelial cells.
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Affiliation(s)
- Yan-Xia Ning
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
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Ning Y, Xu L, Ren S, Pandak WM, Chen S, Yin L. StAR overexpression decreases serum and tissue lipids in apolipoprotein E-deficient mice. Lipids 2009; 44:511-9. [PMID: 19373502 DOI: 10.1007/s11745-009-3299-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 03/24/2009] [Indexed: 02/07/2023]
Abstract
Cholesterol metabolism as initiated by mitochondrial sterol 27-hydroxylase (CYP27A1) is a ubiquitous pathway capable of synthesizing multiple key regulatory oxysterols involved in lipid homeostasis. Previously we have shown that the regulation of its activities within hepatocytes is highly controlled by the rate of mitochondrial cholesterol delivery. In the present study, we hypothesized that increasing expression of the mitochondrial cholesterol delivery protein, steroidogenic acute regulatory protein (StAR), is able to lower lipid accumulation in liver, aortic wall, as well as in serum in a well-documented animal model, apolipoprotein E-deficient (apoE(-/-)) mice. ApoE(-/-) mice, characterized by increased serum, liver, and endothelial cholesterol and triglyceride levels by 3 months of age, were infected with recombinant cytomegalovirus (CMV)-StAR adenovirus to increase StAR protein expression. Six days following infection, serum total cholesterol and triglycerides had decreased 19 and 30% (P < 0.01), respectively, with a compensatory 40% (P < 0.01) increase in serum HDL-cholesterol in increased StAR expressing mice as compared to controls (no or control virus). Histologic and biochemical analysis of the liver demonstrated not only a dramatic decrease in cholesterol ( downward arrow25%; P < 0.01), but an even more marked decrease in triglyceride ( downward arrow56%; P < 0.01) content. En bloc Sudan IV staining of the aorta revealed a >80% (P < 0.01) decrease in neutral lipid staining. This study demonstrates for the first time a possible therapeutic role of the CYP27A1-initiated pathway in the treatment of dyslipidemias.
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Affiliation(s)
- Yanxia Ning
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, PO Box 224, 138 Yixueyuan Road, 200032, Shanghai, People's Republic China
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45
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Bibliography. Current world literature. Nutrition and metabolism. Curr Opin Lipidol 2009; 20:63-72. [PMID: 19106709 DOI: 10.1097/mol.0b013e32832402a2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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46
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Cheung O, Puri P, Eicken C, Contos MJ, Mirshahi F, Maher JW, Kellum JM, Min H, Luketic VA, Sanyal AJ. Nonalcoholic steatohepatitis is associated with altered hepatic MicroRNA expression. HEPATOLOGY (BALTIMORE, MD.) 2009. [PMID: 19030170 DOI: 10.1002/hep.22569;] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
UNLABELLED The expression of microRNA in nonalcoholic steatohepatitis (NASH) and their role in the genesis of NASH are not known. The aims of this study were to: (1) identify differentially expressed microRNAs in human NASH, (2) tabulate their potential targets, and (3) define the effect of a specific differentially expressed microRNA, miR-122, on its targets and compare these effects with the pattern of expression of these targets in human NASH. The expression of 474 human microRNAs was compared in subjects with the metabolic syndrome and NASH versus controls with normal liver histology. Differentially expressed microRNAs were identified by the muParaflo microRNA microarray assay and validated using quantitative real-time polymerase chain reaction (PCR). The effects of a specific differentially expressed miRNA (miR-122) on its predicted targets were assessed by silencing and overexpressing miR-122 in vitro. A total of 23 microRNAs were underexpressed or overexpressed. The predicted targets of these microRNAs are known to affect cell proliferation, protein translation, apoptosis, inflammation, oxidative stress, and metabolism. The miR-122 level was significantly decreased in subjects with NASH (63% by real-time PCR, P < 0.00001). Silencing miR-122 led to an initial increase in mRNA levels of these targets (P < 0.05 for all) followed by a decrease by 48 hours. This was accompanied by an increase in protein levels of these targets (P < 0.05 for all). Overexpression of miR-122 led to a significant decrease in protein levels of these targets. CONCLUSIONS NASH is associated with altered hepatic microRNA expression. Underexpression of miR-122 potentially contributes to altered lipid metabolism implicated in the pathogenesis of NASH.
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Affiliation(s)
- Onpan Cheung
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, VA, USA
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Ogawa S, Kakiyama G, Muto A, Hosoda A, Mitamura K, Ikegawa S, Hofmann AF, Iida T. A facile synthesis of C-24 and C-25 oxysterols by in situ generated ethyl(trifluoromethyl)dioxirane. Steroids 2009; 74:81-7. [PMID: 18996406 DOI: 10.1016/j.steroids.2008.09.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Accepted: 09/19/2008] [Indexed: 10/21/2022]
Abstract
Experiments were performed to compare the regioselective hydroxylation of the isopropyl C-H bond at C-25 in 5alpha-cholestan-3beta-yl acetate by in situ generated dimethyldioxirane, methyl(trifluoromethyl)dioxirane, hexafluoro(dimethyl)dioxirane or ethyl(trifluoromethyl)dioxirane (ETDO). The dioxiranes were generated from the corresponding ketones and potassium peroxymonosulfate in aq. NaHCO(3), pH 7.5-8.0. Of the four dioxiranes examined, partially fluorinated, sterically bulky ETDO displayed the highest reactivity and regioselectivity. Using in situ generated ETDO, a facile, synthesis was developed for two naturally occurring oxysterols, i.e., 25-hydroxycholesterol, as well as its 3-sulfate (overall yield of the sulfate, 24%) and 24-oxocholesterol (16%), starting from cholesterol.
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Affiliation(s)
- Shoujiro Ogawa
- Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan
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Cheung O, Puri P, Eicken C, Contos MJ, Mirshahi F, Maher JW, Kellum JM, Min H, Luketic VA, Sanyal AJ. Nonalcoholic steatohepatitis is associated with altered hepatic MicroRNA expression. Hepatology 2008; 48:1810-20. [PMID: 19030170 PMCID: PMC2717729 DOI: 10.1002/hep.22569] [Citation(s) in RCA: 524] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
UNLABELLED The expression of microRNA in nonalcoholic steatohepatitis (NASH) and their role in the genesis of NASH are not known. The aims of this study were to: (1) identify differentially expressed microRNAs in human NASH, (2) tabulate their potential targets, and (3) define the effect of a specific differentially expressed microRNA, miR-122, on its targets and compare these effects with the pattern of expression of these targets in human NASH. The expression of 474 human microRNAs was compared in subjects with the metabolic syndrome and NASH versus controls with normal liver histology. Differentially expressed microRNAs were identified by the muParaflo microRNA microarray assay and validated using quantitative real-time polymerase chain reaction (PCR). The effects of a specific differentially expressed miRNA (miR-122) on its predicted targets were assessed by silencing and overexpressing miR-122 in vitro. A total of 23 microRNAs were underexpressed or overexpressed. The predicted targets of these microRNAs are known to affect cell proliferation, protein translation, apoptosis, inflammation, oxidative stress, and metabolism. The miR-122 level was significantly decreased in subjects with NASH (63% by real-time PCR, P < 0.00001). Silencing miR-122 led to an initial increase in mRNA levels of these targets (P < 0.05 for all) followed by a decrease by 48 hours. This was accompanied by an increase in protein levels of these targets (P < 0.05 for all). Overexpression of miR-122 led to a significant decrease in protein levels of these targets. CONCLUSIONS NASH is associated with altered hepatic microRNA expression. Underexpression of miR-122 potentially contributes to altered lipid metabolism implicated in the pathogenesis of NASH.
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Affiliation(s)
- Onpan Cheung
- Division of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - Puneet Puri
- Division of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | | | - Melissa J Contos
- Dept. of Pathology, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - Faridoddin Mirshahi
- Division of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - James W. Maher
- Department of Surgery, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - John M. Kellum
- Department of Surgery, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - Haeki Min
- Division of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - Velimir A. Luketic
- Division of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - Arun J. Sanyal
- Division of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
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Ma Y, Xu L, Rodriguez-Agudo D, Li X, Heuman DM, Hylemon PB, Pandak WM, Ren S. 25-Hydroxycholesterol-3-sulfate regulates macrophage lipid metabolism via the LXR/SREBP-1 signaling pathway. Am J Physiol Endocrinol Metab 2008; 295:E1369-79. [PMID: 18854425 PMCID: PMC2603552 DOI: 10.1152/ajpendo.90555.2008] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The oxysterol receptor LXR is a key transcriptional regulator of lipid metabolism. LXR increases expression of SREBP-1, which in turn regulates at least 32 genes involved in lipid synthesis and transport. We recently identified 25-hydroxycholesterol-3-sulfate (25HC3S) as an important regulatory molecule in the liver. We have now studied the effects of 25HC3S and its precursor, 25-hydroxycholesterol (25HC), on lipid metabolism as mediated by the LXR/SREBP-1 signaling in macrophages. Addition of 25HC3S to human THP-1-derived macrophages markedly decreased nuclear LXR protein levels. 25HC3S administration was followed by dose- and time-dependent decreases in SREBP-1 mature protein and mRNA levels. 25HC3S decreased the expression of SREBP-1-responsive genes, acetyl-CoA carboxylase-1, and fatty acid synthase (FAS) as well as HMGR and LDLR, which are key proteins involved in lipid metabolism. Subsequently, 25HC3S decreased intracellular lipids and increased cell proliferation. In contrast to 25HC3S, 25HC acted as an LXR ligand, increasing ABCA1, ABCG1, SREBP-1, and FAS mRNA levels. In the presence of 25HC3S, 25HC, and LXR agonist T0901317, stimulation of LXR targeting gene expression was repressed. We conclude that 25HC3S acts in macrophages as a cholesterol satiety signal, downregulating cholesterol and fatty acid synthetic pathways via inhibition of LXR/SREBP signaling. A possible role of oxysterol sulfation is proposed.
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Affiliation(s)
- Yongjie Ma
- Veterans Affairs McGuire Medical Center/Virginia Commonwealth University, Richmond, VA 23249, USA
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50
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Ning Y, Bai Q, Lu H, Li X, Pandak WM, Zhao F, Chen S, Ren S, Yin L. Overexpression of mitochondrial cholesterol delivery protein, StAR, decreases intracellular lipids and inflammatory factors secretion in macrophages. Atherosclerosis 2008; 204:114-20. [PMID: 18945429 DOI: 10.1016/j.atherosclerosis.2008.09.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 08/29/2008] [Accepted: 09/01/2008] [Indexed: 02/06/2023]
Abstract
Hyperlipidemia is one of the most important risk factors for atherosclerosis. This can be amplified by a localized inflammatory response mediated by macrophages. Macrophages are capable of taking up excess cholesterol, and it is well known that delivery of cholesterol to the mitochondria by steroidogenic acute regulatory (StAR) protein is the rate-limiting step for cholesterol degradation in the liver. It has also been shown that overexpression of StAR in hepatocytes dramatically increases the amount of regulatory oxysterols in the nucleus, which play an important role in the maintenance of intracellular lipid homeostasis. The goal of the present study was to determine whether StAR plays a similar role in macrophages. We have found that overexpression of StAR in human THP-1 monocyte-derived macrophages decreases intracellular lipid levels, activates liver X receptor alpha (LXRalpha) and proliferation peroxysome activator receptor gamma (PPARgamma), and increases ABCG1 and CYP27A1 expression. Furthermore, it reduces the secretion of inflammatory factors, and prevents apoptosis. These results suggest that StAR delivers cholesterol to mitochondria where regulatory oxysterols are generated. Regulatory oxysterols can in turn activate nuclear receptors, which increase expression of cholesterol efflux transporters, and decrease secretion of inflammatory factors. These effects can prevent macrophage apoptosis. These results imply a potential role of StAR in the prevention of atherosclerosis.
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Affiliation(s)
- Yanxia Ning
- Department of Physiology & Pathophysiology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China
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